Add Local GeoJson

GeoJSON geospatial data interchange format based on JavaScript Object Notation (JSON) can support multiple geometries types in one file it’s best to keep them simple and small sized and keep the GeoJSON 4326 geographic wgs84.  QGIS Desktop can create or convert data into GeoJSON. 

 Users can also create geojson online http://geojson.io/#map=2/20.0/0.0 and export for loading into the app.  Users can also use tools like OGR2OGR to convert existing GIS data and databases into GeoJSON